services/surfaceflinger/WindowInfosListenerInvoker.cpp

/*
 * Copyright 2021 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "WindowInfosListenerInvoker.h"
#include <gui/ISurfaceComposer.h>
#include <unordered_set>
#include "SurfaceFlinger.h"

namespace android {

using gui::IWindowInfosListener;
using gui::WindowInfo;

struct WindowInfosReportedListener : gui::BnWindowInfosReportedListener {
    explicit WindowInfosReportedListener(std::function<void()> listenerCb)
          : mListenerCb(listenerCb) {}

    binder::Status onWindowInfosReported() override {
        if (mListenerCb != nullptr) {
            mListenerCb();
        }
        return binder::Status::ok();
    }

    std::function<void()> mListenerCb;
};

WindowInfosListenerInvoker::WindowInfosListenerInvoker(const sp<SurfaceFlinger>& sf) : mSf(sf) {
    mWindowInfosReportedListener =
            new WindowInfosReportedListener([&]() { windowInfosReported(); });
}

void WindowInfosListenerInvoker::addWindowInfosListener(
        const sp<IWindowInfosListener>& windowInfosListener) {
    sp<IBinder> asBinder = IInterface::asBinder(windowInfosListener);

    asBinder->linkToDeath(this);
    std::scoped_lock lock(mListenersMutex);
    mWindowInfosListeners.emplace(asBinder, windowInfosListener);
}

void WindowInfosListenerInvoker::removeWindowInfosListener(
        const sp<IWindowInfosListener>& windowInfosListener) {
    sp<IBinder> asBinder = IInterface::asBinder(windowInfosListener);

    std::scoped_lock lock(mListenersMutex);
    asBinder->unlinkToDeath(this);
    mWindowInfosListeners.erase(asBinder);
}

void WindowInfosListenerInvoker::binderDied(const wp<IBinder>& who) {
    std::scoped_lock lock(mListenersMutex);
    mWindowInfosListeners.erase(who);
}

void WindowInfosListenerInvoker::windowInfosChanged(const std::vector<WindowInfo>& windowInfos,
                                                    bool shouldSync) {
    std::unordered_set<sp<IWindowInfosListener>, ISurfaceComposer::SpHash<IWindowInfosListener>>
            windowInfosListeners;

    {
        std::scoped_lock lock(mListenersMutex);
        for (const auto& [_, listener] : mWindowInfosListeners) {
            windowInfosListeners.insert(listener);
        }
    }

    mCallbacksPending = windowInfosListeners.size();

    for (const auto& listener : windowInfosListeners) {
        listener->onWindowInfosChanged(windowInfos,
                                       shouldSync ? mWindowInfosReportedListener : nullptr);
    }
}

void WindowInfosListenerInvoker::windowInfosReported() {
    mCallbacksPending--;
    if (mCallbacksPending == 0) {
        mSf->windowInfosReported();
    }
}

} // namespace android